Most of the major retailers in the UK have websites that are mobile-friendly, but slow website loading time and the lack of a guest checkout feature are costing them billions in lost revenue.

A study by online retail specialist Summit looked at the UK’s 50 top retailers to show how they could improve their mobile and online activities. Included in the study were John Lewis, Sainsbury’s, Harrods, Tesco, Morrisons and Screwfix.

The study found that the average loading time across all 50 retailers was about seven seconds, which is twice the recommended minimum time. Summit stated that each second above the recommended minimum time cost the retailers 7% in converted sales, which translates into about £1 billion in lost revenue each year.

With regard to guest checkout, the study found that only 38% of the companies surveyed provided that function. With an estimated 25% of online customers leaving an ecommerce website that required registration, Summit estimated that the lack of a guest checkout feature cost the retailers an additional £1 billion in lost revenue each year.

A similar study of 100 online retailers conducted by Bronto Software found that 33% of the companies surveyed did not provide a guest checkout function. This study found that the lack of a guest checkout option required customers to fill out forms on around five pages, with some sites requiring customers to provide information on up to nine pages.

Commenting on the Summit report, TCC Global Global Insights Director Bryan Roberts said: “Even pure play retailers, often held up as being the best-of-the-best when it comes to ecommerce, offer plenty of room for improvement from end-to-end, which is surprising. Shoppers wouldn’t put up with slow service in-store, and the same applies online. Slow site speeds and complex checkout functions can all result in an abandoned basket, just as a long queue can force shoppers into leaving a store.”

In addition to looking at page loading speed and guest checkout options, Summit also looked at the logistics and delivery options offered by the retailers. While 87% offered a click-and-collect feature, most companies surveyed did not offer flexible delivery options. Only 46% offered customers the ability to select the day that they wanted delivery, and only 24% provided the ability to select both the day and time of delivery.

Summit Co-Founder and CEO Hedley Aylott said: “The Summit Scorecard provides us with an understanding of what the top 50 UK retailers are really like to shop with online. While retailers have made huge strides, with most now getting mobile right, many are still struggling to offer delivery options that meet shoppers’ needs. While this will not be an easy fix, no-one in retail needs further convincing or evidence of the importance of the online experience on overall profitability. These results are confirmation that there is still a lot of room for improvement, highlighting the real opportunity for retailers to fix some of the basics.”

On a positive note, the Summit report noted that 92% of the retailers surveyed had a website that was mobile-friendly, an important consideration given the growing trend for consumers to use mobile devices to make purchases online.